The present invention relates generally to the type of golf club heads called metal-wood golf club heads, and more particularly to a cast metal wood golf club head having an improved feel and sound to the golfer during hitting. The present invention also provides an improved method to manufacture such a golf club head.
Golf club heads, particularly "metal woods", have a metal body with a generally flat sole plate, a generally rounded top and a generally flat face extending between them, that face being adapted to strike the ball when the club is swung by means of a shaft. In the production of known metal wood heads, the metal body is formed hollow and a foam material is filled into the cavity in the metal body. The foam material is used so as to reduce an undesirable metallic sound that is made by an empty metal wood head during hitting. The foam material is designed to have a consistent cellular structure throughout the cavity. In practice, however, that consistency is hard to achieve and voids often form in the foam, making for unpredictability in hitting the golf ball because of the difference in a solid hit often identified through the reduction in the metallic sound and feel through the swing process.
Attempts have been made to improve this type of golf club head. U.S. Pat. No. 5,135,227 discloses a metal wood-type golf club head with a hollow metal head body and a core material filling the hollow, wherein the core material is an aggregate of fused expandable beads that form uniformly dispersed cells. A club head according to that invention is supposed to give a lengthened shot and to reduce the metallic sound made during hitting.